A detection of a touch sensor includes a capacitance-type detection which responds to an electric power which flows through a finger in contact with a screen to transform the motion of the finger into an operation command. There is disclosed a capacitance sensor using such a capacitance-type detection in which an auxiliary electrode having an electric resistance lower than that of a transparent electrode is formed in at least a portion of the periphery of the transparent electrode so as to suppress a variation in detection sensitivity. For more detail, see, for example, Patent Document 1.
However, in a case where misalignment between the transparent electrode and the auxiliary electrode occurs during the manufacture of the sensor as disclosed in Patent Document 1, the conduction area between the transparent electrode and the auxiliary electrode may be variable depending on an amount of misalignment. If the transparent electrode and the auxiliary electrode are intended to be precisely aligned in order to avoid such a variation in the conduction area between the transparent electrode and the auxiliary electrode due to the misalignment, the process for manufacturing the sensor become inevitably complicated. In order to overcome this drawback, there has been proposed that the contour line of a light transmitting resist is located on the contour line of the transparent electrode which is not covered by the auxiliary electrode to improve the positioning accuracy between the transparent electrode and the auxiliary electrode. For more detail, see, for example, Patent Document 2.
However, Patent Document 1 teaches conductive paste containing conductive metallic material with low resistance such as silver ink or a metallic layer as the material for the auxiliary electrode, and Patent Document 2 teaches an ink containing metallic particles of silver, copper, gold and the like, an ink containing carbon or graphite, a metallic film and the like as the material for the auxiliary electrode. In a case where the auxiliary electrode is formed of the material which is different from the material for the transparent electrode, as described in Patent Document 1 and Patent Document 2, the problems or drawbacks are as follows: (i) the auxiliary electrode which is disposed at the periphery of the transparent electrode outstands to compromise the appearance or designing properties; (ii) as there is created a great level difference between the transparent electrode and the auxiliary electrode, during the formation of an covering over these transparent and auxiliary electrode, air bubble entrapped in the covering leads to the increase in parasitic capacitance; (iii) due to the auxiliary electrode the viewable area of the transparent electrode is reduced; and (iv) as the material such as silver and gold is expensive, material cost increases.